Electronic Structure of Semiconductor Interfaces

✍ Scribed by Winfried Mönch

• Publisher: Springer
• Year: 2024
• Tongue: English
• Leaves: 156
• Series: Synthesis Lectures on Engineering, Science, and Technology
• Category: Library

✦ Synopsis

This concise volume examines the characteristic electronic parameters of semiconductor interfaces, namely the barrier heights of metal–semiconductor or Schottky contacts and the valence-band discontinuities of semiconductor–semiconductor interfaces or heterostructures. Both are determined by the same concept, namely the wave-function tails of electron states overlapping a semiconductor band gap directly at the interface. These interface-induced gap states (IFIGS) result from the complex band structure of the corresponding semiconductor. The IFIGS are characterized by two parameters, namely by their branch point, at which their charge character changes from predominantly valence-band- to conduction-band-like, and secondly by the proportionality factor or slope parameter of the corresponding electric-dipole term, which varies in proportion to the difference in the electronegativities of the two solids forming the interface. This IFIGS-and-electronegativity concept consistently and quantitatively explains the experimentally observed barrier heights of Schottky contacts as well as the valence-band offsets of heterostructures. Insulators are treated as wide band-gap semiconductors.

✦ Table of Contents

Preface
Contents
1 Introduction
1.1 Metal–Semiconductor Rectifiers
1.2 Metal-Induced Gap States
1.3 Semiconductor Heterostructures
2 Experimental Data Base
2.1 I/V Characteristics of Schottky Contacts: Barrier Height and Ideality Factor
2.2 C/V Characteristics of Schottky Contacts: Flat-Band Barrier Height
2.3 I/V and C/V Characteristics of Ag/n-Si(111) Schottky Contacts
2.3.1 Three Mechanisms
2.4 Laterally Inhomogeneous or “Patchy” Schottky Contacts
2.5 Extrinsic Interface Dipoles
2.5.1 The Si(111)–(7 × 7)i Interface Reconstruction
2.5.2 H-modified Schottky Contacts
2.6 Specific Experimental Results
2.6.1 Crystallographic Orientation of the Semiconductor
2.6.2 P- and n-Type Schottky Contacts
2.6.3 Schottky Contacts of SiC Polytypes
3 From the Schottky–Mott Rule to Interface-Induced Gap States
3.1 Schottky–Mott Rule
3.2 Bardeen’s Solution: Interface States
3.3 Cowley-Sze Modell: Schottky–Mott Modell Plus Interface States
3.4 Critique of the Use of Surface Properties
3.5 Formation of Schottky Contacts
3.5.1 Adatom-Induced Surface States and Dipoles
3.5.2 Adatom-Induced Surface Core-Level Shifts
3.5.3 Electronegativity Concept: Si and InP Schottky Contacts
3.6 Metal-Induced Gap States
3.7 Metal–Semiconductor Contacts and MIGS
3.8 Semiconductor Heterostructures
3.8.1 Anderson’s Rule
3.8.2 Heterostructures and Interface-Induced Gap States
3.8.3 Determination of Valence-Band Offsets
4 Interface-Induced Gap States
4.1 Calculated Branch-Point Energies
4.2 Slope Parameters
5 Comparison of Theoretical and Experimental Data
5.1 p-Type Schottky Contacts
5.1.1 Experimental Data
5.1.2 Branch-Point Energies Φbpp
5.1.3 Slope Parameters SX
5.2 n-Type Schottky Contacts and Heterostructures
5.2.1 Diamond
5.2.2 Silicon
5.2.3 Germanium
5.2.4 Silicon Carbide 3C-, 4H- and 6H-SiC
5.2.5 Gallium Arsenide GaAs
5.2.6 Gallium Nitride GaN
5.2.7 Aluminum Nitride AlN
5.2.8 Indium Nitride InN
5.2.9 Gallium Oxide Ga2O3
5.2.10 Aluminum Oxide Al2O3
5.2.11 Silicon Dioxide SiO2
5.2.12 Silicon Nitride Si3N4
5.2.13 Strontium Titanate SrTiO3
6 Irradiation- or Native-Defect-Induced Gap States
7 Conclusions
Appendix
References